Furthermore, the invention relates to a field device and a servicing device for performing the method, as well as to a computer program product.
Known from the state of the art are methods, by means of which a field device can be serviced, for example, based on a device description (abbreviated DD). The device description describes the device functionalities of a field device. Via the device description, particular commands available in a protocol can be linked with particular functionalities of a field device. The commands which can be used therefor are predetermined by the basic protocol, which the field device understands, in order, for example, to be able to communicate via a fieldbus to which it is connected.
Such methods are executed, for example, in the form of programs. By means of these programs, a user can transmit data to the field device or obtain data from the field device, data which serve for controlling the plant, the processes running therein or the field device itself. The data are, in such case, transmitted between the program and the field device. The transmission path is, for example, a wired, or wireless, fieldbus. The aforementioned programs can be, for example, one of the programs AMS, POM, Fieldcare, FieldXpert or FieldCommunicator.
Field devices used in process and automation technology can communicate, for example, according to the HART protocol, the Profibus or the FOUNDATION Fieldbus protocol. These protocols have different types of commands. For one, there are the basic commands, which each field device compatible with the corresponding fieldbus protocol must have available.
There furthermore exists a group of commands, which are referred to as “common practice commands” and upon which the various manufacturers have agreed. For example, field devices of a specific type, for example, flow measuring devices, have available a certain number of “common practice commands”.
There exist, moreover, so-called “device specific commands” by means of which special functions of a particular field device can be invoked. These commands are predetermined by the manufacturer of a field device specifically for such field device and/or its purpose of use. A control unit for an industrial plant must know these commands, in order to assure the operation of the plant and/or in order to be able to completely configure the field devices to the predetermined requirements. Attention must especially be paid in such case that the same command is not assigned multiple times and triggers different functions in different field devices.
Given that these different servicing programs are available, it is known from the state of the art also to create a unique driver, i.e. a unique device description, for each.